Fire Distribution Research Articles

Historical and future global burned area with changing climate and human demography

Summary Wildfires influence terrestrial carbon cycling and represent a safety risk, and yet a process-based understanding of their frequency and spatial distributions remains elusive. We combine satellite-based observations with an enhanced dynamic global vegetation model to make regionally resolved global assessments of burned area (BA) responses to changing climate, derived from 34 Earth system models and human demographics for 1860–2100. Limited by climate and socioeconomics, recent BA has decreased, especially in central South America and mesic African savannas. However, future simulations predict increasing BA due to changing climate, rapid population density growth, and urbanization. BA increases are especially notable at high latitudes, due to accelerated warming, and over the tropics and subtropics, due to drying and human ignitions. Conversely, rapid urbanization also limits BA via enhanced fire suppression in the immediate vicinity of settlements, offsetting the potential for dramatic future increases, depending on warming extent. Our analysis provides further insight into regional and global BA trends, highlighting the importance of including human demographic change in models for wildfire under changing climate.

Tussocks Enduring or Shrubs Greening: Alternate Responses to Changing Fire Regimes in the Noatak River Valley, Alaska

AbstractAs the Arctic warms, tundra wildfires are expected to become more frequent and severe. Assessing how the most flammable regions of the tundra respond to burning can inform us about how the rest of the Arctic may be affected by climate change. Here we describe ecosystem responses to tundra fires in the Noatak River watershed of northwestern Alaska using shrub dendrochronology, active‐layer depth monitoring, and remotely sensed vegetation productivity. Results show that relatively productive tundra is more likely to experience fires and to burn more severely, suggesting that fuel loads currently limit tundra fire distribution in the Noatak Valley. Within three years of burning, most alder shrubs sampled had either germinated or resprouted, and vegetation productivity inside 60 burn perimeters had recovered to prefire values. Tundra fires resulted in two phases of increased primary productivity as manifested by increased landscape greening. Phase one occurred in most burned areas 3–10 years after fires, and phase two occurred 16–44 years after fire at sites where tundra fires triggered near‐surface permafrost thaw resulting in shrub proliferation. A fire‐shrub‐greening positive feedback is currently operating in the Noatak Valley and this feedback could expand northward as air temperatures, fire frequencies, and permafrost degradation increase. This feedback will not occur at all locations. In the Noatak Valley, the fire‐shrub‐greening process is relatively limited in tussock tundra communities, where low‐severity fires and shallow active layers exclude shrub proliferation. Climate warming and enhanced fire occurrence will likely shift fire‐poor landscapes into either the tussock tundra or erect‐shrub‐tundra ecological attractor states that now dominate the fire‐rich Noatak Valley.

Spatiotemporal patterns of burned areas, fire drivers, and fire probability across the equatorial Andes

Field-based fire studies in the equatorial Andes indicate that fires are strongly associated with biophysical and anthropogenic variables. However, fire controls and fire regimes at the regional scale remain undocumented. Therefore, this paper describes spatial and temporal burned-area patterns, identifies biophysical and anthropogenic fire drivers, and quantifies fire probability across 6° of latitude and 3° of longitude in the equatorial Andes. The spatial and temporal burned-area analysis was carried out based on 18 years (2001–2018) of the MCD64A1 MODIS burned-area product. Climate, topography, vegetation, and anthropogenic variables were integrated in a logistic regression model to identify the significance of explanatory variables and determine fire occurrence probability. A total of 5779 fire events were registered during the 18 years of this study, located primarily along the western cordillera of the Andes and spreading from North to South. Eighty-eight percent of these fires took place within two fire hotspots located in the northwestern and southwestern corners of the study area. Ninety-nine percent occurred during the second part of the year, between June and December. The largest density of fires was primarily located on herbaceous vegetation and shrublands. Results show that mean monthly temperature, precipitation and NDVI during the pre-fire season, the location of land cover classes such as forest and agriculture, distance to roads and urban areas, slope, and aspect were the most important determinants of spatial and temporal fire distribution. The logistic regression model achieved a good accuracy in predicting fire probability (80%). Probability was higher in the southwestern and northern corners of the study area, and lower towards the north in the western and eastern piedmonts of the Andes. This analysis contributes to the understanding of fires in mountains within the tropics. The results here presented have the potential to contribute to fire management and control in the region.

The distribution and treatment of fire remains across Unit V of the Middle Paleolithic open-air site of Nesher Ramla, Israel

While abundant evidence for the use of fire has been identified for the Paleolithic period in the Levant, little evidence has come from open-air sites. This scarcity has brought into question the preservation potential of fragile fire remains at this type of site, which is normally exposed to wind deflation and fluvial erosion, and whether or not fire was used at all. A recently discovered site inside a karstic sinkhole at Nesher Ramla, Israel shows promise of filling this knowledge gap. With abundant evidence for well-preserved human activities, including the preservation of combustion features, this Middle Paleolithic site provides a glimpse into the use of fire at open-air sites. This study aims to provide a clearer picture of the spatial distribution of fire residues across the richest unit at Nesher Ramla, Unit V, and to identify possible behaviors associated with the use of fire. The presence of burned bones and ash pseudomorphs across this unit shows that fire activities were indeed prevalent at the site. However, the relatively low concentrations of ash pseudomorphs require an explanation. Two options are discussed: a short-term occupation (hours to a few days) or the partial preservation of the ash pseudomorphs. The presence of these fire remains in nearly every sample, with slightly higher concentrations coming from the eastern part of the unit, suggests more intensive occupation and their reworking across the site, potentially unintentionally by trampling or intentionally by sweeping and depositing the ash in a specified dump area. In addition to supporting previous research suggesting intensive occupation (e.g. via artifact densities) associated with combustion remains at Unit V of Nesher Ramla, the results of this study further shed light on behaviors associated with the treatment of fire remains and partitioned use of space at open-air sites.

Importance of Uncertainties in the Spatial Distribution of Preindustrial Wildfires for Estimating Aerosol Radiative Forcing

AbstractUncertainty in preindustrial aerosol emissions, including fires, is one of the largest sources of uncertainty in estimating anthropogenic radiative forcing. Here, we quantify the range in aerosol forcing associated with uncertainty in the location and magnitude of preindustrial fire emissions in a climate model based on four emission estimates. With varied emission location and magnitude among the fire estimates, we find the change in aerosol forcing from present‐day to preindustrial is between −0.4 and 0.3 W/m2 for direct radiative forcing and between −1.8 and 0.6 W/m2 for cloud albedo forcing. Altering only the spatial distribution of preindustrial fires for a fixed magnitude adds a previously unaccounted 25% uncertainty to the total aerosol radiative forcing range. Future studies must account for the uncertainty in the spatial distribution of fire and other aerosol emissions as regional differences contribute substantial additional uncertainty to anthropogenic radiative forcing estimates and the resultant climate sensitivity.

A hydroclimatic model for the distribution of fire on Earth

The distribution of fire on Earth has been monitored from space for several decades, yet the geography of global fire regimes has proven difficult to reproduce from interactions of climate, vegetation, terrain, land use and other human activities by empirical and process-based fire models. Here, we propose a simple, yet robust, model for the global distribution of fire potential based on fundamental biophysical constraints controlling fire activity in all biomes. In our ‘top-down’ approach we ignored the dynamics of individual fires and focus on capturing hydroclimatic constraints on the production and (seasonal) desiccation of fuels to predict the potential mean annual fractional burned area at 0.25° spatial resolution, here estimated by the 0.99 quantile of the observed mean annual fractional burned area () over the 1995-2016 period of the Global Fire Emissions Database (GFED4). We show that 80% of the global variation in can be explained from a combination of mean annual precipitation and potential evapotranspiration. The proposed hydroclimatic model reproduced observed 0.99 quantile fire activity levels equally well across all biomes and provided the first objective underpinning for the dichotomy of global fire regimes in two domains characterised by either fuel production limitations on fire or fuel dryness limitations on fire. A sharp transition between the two climate-fire domains was found to occur at a mean annual aridity index of 1.9 (1.94 ± 0.02). Our model provides a simple but comprehensive basis for predicting fire potential under current and future climates, as well as an overarching framework for estimating effects of human activity via ignition regimes and manipulation of vegetation.

Spatial and temporal distributions of forest fires in Heilongjiang Province from 2001 to 2018 based on MODIS data

Spatial and temporal distributions of forest fires in Heilongjiang Province from 2001 to 2018 based on MODIS data

The impact of biomass burning emissions on protected natural areas in central and southern Mexico.

Biomass burning from grassland, forests, and agricultural waste results in large amounts of gases and particles emitted to the atmosphere, which affect air quality, population health, crop development, and natural vegetation. Regional atmospheric circulations can transport those plumes of pollutants over hundreds of kilometers, affecting vulnerable environments such as those considered protected natural areas (PNAs). This study evaluates the spatiotemporal distribution of active fires detected, and associated emissions, in central and southern Mexico from satellite data between March and June 2017, to assess the impact of the smoke plumes on protected ecosystems. The arrival of smoke plumes to selected PNAs (both near large urban centers and in remote areas) is assessed using airmass forward trajectories from selected emission sources. The spatial distribution of the remotely derived aerosol optical depth confirms the regional impact of particle emissions from the observed fires on PNAs, particularly in central Mexico. The identified areas of high fire density are also associated with large coarse particle concentrations at the surface. Moreover, there is a significant contribution of organic carbon to the total coarse particle mass, 60% on average. Finally, while most of the impact in ambient pollution is observed in PNAs located close to the regions with active fires in southern Mexico and Central America, the long-range transport of smoke plumes reaching the USA was also confirmed.

Спутниковая оценка гибели древостоев от пожаров по данным о сезонном распределении пройденной огнем площади

Спутниковая оценка гибели древостоев от пожаров по данным о сезонном распределении пройденной огнем площади

<i>Corrigendum to</i>: Spatial correlates of forest and land fires in Indonesia

Biomass fires in Indonesia emit high levels of greenhouse gases and particulate matter, key contributors to global climate change and poor air quality in south-east Asia. In order to better understand the drivers of biomass fires across Indonesia over multiple years, we examined the distribution and probability of fires in Sumatra, Kalimantan (Indonesian Borneo) and Papua (western New Guinea) over four entire calendar years (2002, 2005, 2011 and 2015). The 4 years of data represent years with El Niño and La Niña conditions and high levels of data availability in the study region. Generalised linear mixed-effects models and zero-inflated negative binomial models were used to relate fire hotspots and a range of spatial predictor data. Geographic differences in occurrences of fire hotspots were evident. Fire probability was greatest in mixed-production agriculture lands and in deeper, degraded peatlands, suggesting anthropogenic activities were strong determinants of burning. Drought conditions in El Niño years were also significant. The results demonstrate the importance of prioritising areas of high fire probability, based on land use and other predisposing conditions, in effective fire management planning.

Пирогенное преобразование геосистем Западного Прибайкалья: факторы, условия, современное состояние

The factors of pyrogenic impact on the taiga geosystems of the Western Baikal region against the background of the modern transformation of the global atmospheric circula-tion are studied in the paper. The results of world scientific research on modeling climate change and related adverse weather phenomena (prolonged droughts, thunderstorm activity, etc.) are presented. The natural factors contributing to the increase in the pyrogenic transformation of geosystems are described. The study of the spatio-temporal distribution of fires is carried out on the basis of data from remote sensing of the Earth. Information about unfavorable weather conditions and dangerous hydrometeorological phenomena, data on atmospheric phenomena (thunderstorm activity), daily values of air temperature and soil temperature under natural cover at different depths are analyzed in order to factorial analysis of forest fire sources in the study area. The characteristic of the current stage of geosystems is given based on field research conducted in June 2020. It was revealed that catastrophic fires registered in the study area in 1997 and 2015 occurred against the background of minimal thunderstorm activity. At the same time, in the central part of the Western Baikal region thunderstorms were the leading factor in the 2015 fires. Five years after the fire, the restoration of mountain taiga light coniferous forests is characterized by the predominance of the community of Chamaenerion angustifolium (L.) Scop. The successional dynamics of the geosystems of mountain taiga dark coniferous forests is going through the Betula rotundifolia Spach. with Ledum palustre L. and cereal-forb ground cover. Undergrowth of tree species (mainly pine) is rare and uneven about 800–1200 specimens per hectare.

Propagation Analysis of Pu Radionuclides as a Result of Fire Incidents in the Exclusion Zone of the Chernobyl NPP in April 2020

In consequence of nuclear accidents that have occurred in various parts of the world, radioactive contamination of the environment is observed. The risks of spreading pollution can increase during floods, fires and some natural disasters. The lack of effective measures that aimed at eliminating possible sources of fire in the meadow zone and forest lands in the Chernobyl exclusion zone (ChEZ) leads to a high risk of fire emergence. The temporal and spatial distribution of fires shows that they occur throughout the ChEZ, including in the most contaminated areas. The risk of fires increases with climate change and measures to prevent them should be considered in emergency programs. ChEZ area is contaminated with long-lived radionuclides such as 137Cs, 90Sr, Pu isotopes (238Pu, 239 + 240Pu, 241Pu) and 241Am. As a result of forest fires radionuclides contained in wood and underlying surface are carried out into the atmosphere along with smoke. Diseases arising under the influence of ionizing radiation from Pu and 241Am isotopes pose a serious problem for human health. To assess of the spatial distribution of Pu isotopes and 241Am we used data on forest fires that occurred in the Chernobyl zone in April 2020. To evaluatе the dynamics of the release of radioactive substances into the atmosphere during fire incidents on the ChEZ territory, the following software products were used: NASA WorldView, HYSPLIT program. The HYSPLIT program allows to reconstruct the trajectories of radionuclide propagation in the atmosphere using meteorological data and to obtain a reliable picture of the distribution of radionuclides in the study area. The maps of the volumetric activity of Pu isotopes in the air and the fallout on the soil as a result of fires were obtained. It was found that the radioactivity due to the presence of this element in the air and during the fallout of radioactive particles on the soil is low (it reaches 1.0E-7...0.1 Bq/m3 in the air, 1.0E-6...1 Bq/m2 on the soil). The analysis of the propagation of Pu isotopes as a result of the movement of air masses in the places of fires in the exclusion zone of the Chernobyl nuclear power plant and the associated dangers for the population and the environment has been carried out.

A Principal Component Analysis-Boosted Dynamic Gaussian Mixture Clustering Model for Ignition Factors of Brazil’s Rainforests

Analysis of Brazil’s rainforest fires caused by various factors has become a hot topic nowadays,. Mining of rainforest fire data through learning unlabeled training samples can reveal inherent properties and patterns, providing a clue for fire prevention. Among commonly used mining approaches, clustering algorithms based on density estimation can relatively effectively capture the potential ignition features through probability calculation, while the Gaussian mixture model (GMM) based on Expectation-Maximum (EM) can effectively quantify fire distribution curves and decompose a fire object into different shape clustering problems based on the actual distribution characteristics of fires data, and thus cluster fires more accurately. However, when the discrimination of probability density is not apparent, the clustering effect is susceptible to both the number of parameters used in clustering and the shape of the clustering problem. Therefore, in the present paper, based on a new strategy of selecting and updating the parameters in the GMM, a new hybrid clustering model called Principal Component Analysis-boosted Dynamic Gaussian Mixture Clustering model (PCA-DGM) is developed. Specifically, Principal Component Analysis (PCA) reduces the dimension of fire samples and strengthens key ignition features. Furthermore, a new dynamic distance loss function is developed by dynamically selecting density parameters or distance parameters, whose computing value is utilized as one important parameter of the clustering shape decision of the GMM. Using the PCA-DGM, which can effectively solve clustering problems with various shapes, the causes of forest fires in Brazil are analyzed at both the temporal and geographical levels, and the experimental results demonstrate that the proposed PCA-DGM in this paper has a better clustering effect than the other traditional clustering algorithms.

Analysis of the Capture Rate of Barrel Weapon Test Based on Laser Screen Velocity Measurement System

The flying velocity is a key parameter of the projectile in the exterior ballistic test, which is usually measured by the laser screen velocity measurement system. However, how to set the system parameters reasonably to ensure the system capture rate is a challenge due to the insufficient research. In order to solve this problem, our research reveals the change law of the system capture rate by deriving the mathematical model and simulation based on the principle of system detection and the gun firing distribution law. With the three system settings in the simulation, the critical height of the muzzle are 3.78m, 4.1m, and 3.9m respectively. Within the critical height, the system capture rate is greater than 99% theoretically. If it exceeds the critical height, the system capture rate will drop rapidly to 0. In addition, changing the laser power or the arrangement of the detection devices during the test will affect the system capture rate. To verify the simulation result, we perform a gun shoot experiment, fully confirming our analyses.

The Influence of Land Cover on the Spatial Distribution of Fire Sites: A Case Study of Łódzkie Voivodeship, Poland

The paper continues from previous joint studies and their practical application at the confluence of human geography, safety-related research and Geographic Information Systems (GIS). The objective of the study was to identify the land cover types most at risk from fire. The study has contributed an original angle by taking into account various land cover types with a potential influence on the distribution of fires geocoded at the address level. The analysis considered 27,651 fire interventions, as recorded by the Polish State Fire Service between 2014 and 2016 in the country’s central region known as Łódzkie Voivodeship. The main methods employed include various GIS tools, including Voronoi tessellation (to identify the areas most at risk of fire) and the fire location quotient (FLQ, a measure of the colocation between the number of fires and land cover). The most important conclusion is that of all the land cover types considered in the study, the built-up area type, especially the multi-family residential and retail and service area subtypes, was virtually the only one with a strong influence on the location of fires. The fire high-risk areas (FH-RA) identified here were primarily limited to urban areas.

A Monte Carlo simulation study on probability distribution of urban tunnel fire

Urban tunnel traffic has its inherent charateristics, such as frequently periodical traffic congestion/blocking, tidal phenomenon, large traffic flow and population, complicated traffic confluences and cross-flowing intertwined sections. Unlike ordinary roads, the potential fire scenarios are quite different and the consequences of fire are extremely severe in urban tunnel. The study adopts theoretical calculation, formula derivation, traffic survey, random sampling simulation to explore the probability distribution of urban tunnel fire. MATLAB is used to realize the numerical simulation of a million fire scenarios under different working conditions. The results identify the major factors affecting two-lane tunnel vehicle ignition model and three-lane model respectively. The probability of six combustion scales (, , , , and ) is higher than that of others, and with the increase of combustion scale, the probability decreasing exponentially. The ratio of truck to bus has a significant impact on the probability of large-scale fire. And truck fire and bus fire have a risk of igniting vehicles in adjacent lanes. The research results provide a basis for the design parameters of evacuation safety in practical engineering.

COMPARISON BETWEEN DIFFERENT VERSIONS OF INPE'S FIRE RISK MODEL FOR THE BRAZILIAN BIOMES

Abstract. Fires are intrinsic disturbances in ecosystems functioning and structure in fire-prone biomes. In recent decades there has been an increase in the number of fire events in Brazilian biomes, especially due to misuse of fire in the land use and deforestation. The spatial and temporal pattern fire risk is a important way to understanding the seasonality and intensity of fire in different climate and fuel conditions. However, consistent long-term assessment at biome level is only possible with the support of remote sensing and modeling information. Thus, the objective of this work was to evaluate the fire risk patterns for the Brazilian biomes in the last years (2015–2018), using the new version of INPE’s fire risk (FR, v2). Regarding the temporal and spatial FR patterns by this new version from FR model, we evaluated that elevation and latitude correction factors, as well as the meteorological and land cover datasets with finer spatial scales can be contributed to adjust better the fire season vulnerability, notably in the less prone-biomes, such as Mata Atlantica, Pampa and Pantanal. However, there is still a need for adjustment to match the spatial active fire distribution, considering a biomass (fuel) map and the vegetation water status indicators. These improvements help to inform with more accuracy the most fire prone areas to define the strategies and decisions for fire combat and management.

Research on axial temperature distribution of annular pool fires of floating roof tanks

Research on axial temperature distribution of annular pool fires of floating roof tanks

Extracting a History of Global Fire Emissions for the Past Millennium From Ice Core Records of Acetylene, Ethane, and Methane

AbstractBiomass burning is an important component of the Earth system in terms of global biogeochemistry, atmospheric composition, climate, terrestrial ecology, and land use. This study examines published ice core trace gas measurements of acetylene, ethane, and methane, which have been used as proxies for paleofire emissions. We investigate the consistency of these records for the past 1,000 years in terms of (1) temporal trends in global fire emissions and (2) quantitative estimates for changes in global burning (dry matter burned per year). Three‐dimensional transport and box models were used to construct emissions scenarios for the trace gases consistent with each ice core record. Burning histories were inferred from trace gas emissions by accounting for biome‐specific emission factors for each trace gas. The temporal trends in fire inferred from the trace gases are in reasonable agreement, with a large decline in biomass burning emissions from the Medieval Period (MP: 1000–1500 CE) to the Little Ice Age (LIA: 1650–1750 CE). However, the three trace gas ice core records do not yield a consistent fire history, even assuming dramatic (and unrealistic) changes in the spatial distribution of fire and biomes. Substantial changes in other factors such as meteorological transport or atmospheric photochemical lifetimes appear to be required to reconcile the trace gas records.

Análise de causa e influência de elementos meteorológicos em ocorrências de incêndios em florestas de produção

A quantidade e intensidade dos incêndios florestais têm sido destaque mediante as perdas e os impactos sociais, ambientais e econômicos. Dessa forma, o objetivo desta pesquisa foi identificar o perfil dos incêndios assim como suas causas e correlacionar a influência dos elementos meteorológicos sob as ocorrências de incêndios em florestas de produção para direcionar o uso de recursos em técnicas e medidas de prevenção, além de estruturas de combate aos incêndios florestais. O estudo teve como subsídio o banco de dados da série histórica de 10 anos de registro de ocorrência de incêndios e de variáveis meteorológicas oriundas de 45 estações meteorológicas de uma empresa produtora de eucalipto para celulose, no período de 2008 a 2017. De acordo com os resultados, 91,40% das 32.561 ocorrências ao longo dos 10 anos foram originadas por incendiários. Além disso, justificado pela causa do incêndio, a quantidade de ocorrências entre os anos analisados apresentou correlações negativas moderada e baixa respectivamente, para umidade relativa e precipitação e correlação desprezível para temperatura média. A distribuição mensal dos incêndios destacou-se por ser uniforme ao longo do ano, uma vez que, apesar de setembro e outubro apresentarem a maior incidência das ocorrências, eles diferiram apenas de abril ao nível de 5% de probabilidade pelo teste de Tukey. Dessa forma, regiões onde a origem dos incêndios florestais é majoritariamente por ação intencional e criminosa, as ações de prevenção, monitoramento, registro de informações confiáveis e combate aos incêndios florestais devem ser planejadas contemplando todos os meses do ano.